测试

public class Duck{  private int size=0;  public void setsize1(int size){   size=size;  }  public void setsize2(int size){   this.size=size;  }  public static void main(String[] args){   Duck duck1=new Duck();   duck1.setsize1(10);   System.out.println("duck1.size="+duck1.size);   Duck duck2=new Duck();   duck2.setsize2(10);   System.out.println("duck2.size="+duck2.size);   } }